This invention relates to improved feeding apparatus for a disc refiner. Its features are particularly advantageous for use in a double revolving disc refiner and will be so described, though not necessarily so limited in application.
Feeding of raw materials such as wood chips or pulp to a disc refiner, particularly with a high degree of consistency, has always been a problem, in one way or another. For one thing, the energy applied to the disc refining operation is converted to heat and converts, in turn, the moisture or water present to steam. This steam backflows and interferes with the delivery of material to be refined. The pressure and amount of this backflow is sometimes so great as to completely block the inflow of material to the refiner disc. The disruption of the inflow in this manner, at the least, causes erratic motor loading and wastes energy, as well as has an adverse effect on stock quality. Other problems exist due to the difficulty of properly constructing the apparatus to channel the material fed to the refiner discs in a manner to minimize the adverse effects of backflowing steam.
Much time and money has been put into efforts to solve the above noted problem. There has been a development of various types of "improved" material feeding apparatus with varying degrees of success for some applications. However, the results have not been totally satisfactory. The present day economics of pulp refining demand feeding apparatus that is more versatile and adaptable in application and less prone to misfunction or malfunction than that heretofore offered in the trade.
The present invention materially alleviates the problems heretofore met in feeding disc refiners, particularly double revolving disc refiners, in its provision of an improved coaxial feeder. The feeders of this classification, including art quite remote in contemplation from a feeder for a disc refiner pertinent to the present invention of which those substantively involved in this disclosure are aware, and which have been considered to determine the novelty of the present invention consist of the following publications:
U.S. Pat. Nos. 3,467,323 A. Asplund et al Sept. 16, 1969; 4,082,233 R. B. Reinhall Apr. 4, 1978; 3,074,656 L. N. Christensen et al Jan. 22, 1963; 2,064,666 A. Krushel Dec. 15, 1936; 1,114,657 E. Twigg Oct. 20, 1914; 1,078,517 M. E. Rozelle Nov. 11, 1913; 3,420,458 A. J. Yli-Paavola Jan. 7, 1969.